I finally got all the bolt-on-power upgrades installed... With the recent addition of the Hi-flow cat(n-tech) I again have boost creep/spikes to - beyond 15psi(not good) when my secondondary kicks in. I also have little to no boost in 1st & 2nd gear(see other post)

My question is: If I convert to Non-Seq will I still have boost creep due to the increased flow? Or does non-seq. eliminate this? My guess would be no? But then again, I don't know sh%t...

Will I still have to port my wastegate?

John

 

You haven't ported your wastegate with those mods?! You're problem is that you have WAY too much exhaust for the stock-ported wastegate to handle and thus your turbos continue to spool up even when your wastegate is wide open.

 

Jonski,

Did you port your own waste gate or did you have shop do it? How much does it ususally cost have someone do the porting?

John

 

My only mods are gutted pre-cat and Pettit AST. Since this car is my daily driver, I don't want to worry about the issues that tag along with performance upgrades (e.g. boost creep). If you want a temporary fix for your boost creep, then you need some back pressure to slow down the exhaust flow. The stock cat-back and/or main cat would do nicely, if you still have either of them. Getting at the wastegate is no light undertaking. Some people pull their engine to get at the turbos. If you have never worked under the hood before, then have a shop port it for you. I have no idea what it would cost, though. If you are intent on doing it yourself, then find a willing enthusiast who has done it to help you, but try an easier project first, like the air box mod or AST replacement.

 

JONSKI's correct. I am one of the few people who is ALSO going to pull my engine to get at my turbos.

 

OK, I've done some research. Porting the wastegate is the best way to stop boost creep. However, you have to remove the turbos to get at the internal wastegate. Too big of a job for this newbie... So I called a local roatry shop to see how much they'd charge. Homie said it would take around 7-8 hours at $80 bucks=$500-600!

So after much searching and Pming(*thanks Rikki), I've decided to try a restrictor plate. Basically, a metal plate that goes in between the hi-flow cat and the cat back with a smaller diameter hole cut into to it to restrict the flow of the exhaust gas.

Before I go build one, does anyone have an extra restrictor plate lying around that they would give/sell to me????

John
jpandes@hotmail.com
415-609-2341

 

You have another option. You could sell your M2 for a PowerFC instead, then you will be able to run an open mid-pipe and not have to worry about a restrictor plate.

That's what I did, I had horrible creep with the M2 and I had to use a restrictor plate. So I bought a PFC instead and I get the EXACT amount of boost every time, it controls it very well IMO.

If you want to try a restrictor, try this , it worked well for me: http://www.jegs.com/cgi-bin/ncommerc...71&prmenbr=361

 

I've access to a lift and power tools, but the problem is the DAMN STEERING RACK!!! It would be SO easy without all that crap there. I can have the engine ready to pull out in about 45 minutes...and have it pulled out within 1 hour.

 

Just thought I'd throw in my experience with the Power FC: *with* a ported wastegate, I would still creep to 13-14 psi when I had my midpipe. I'm not sure a power fc is the definitely the answer. Try the restrictor plate, or.....get a high flow cat. I thought I would hate going from the mid pipe to a high flow, but I'm pretty happy with it. Nicer exhaust tone, more low end, safer in general re: leaning out/creep, and I still made pretty damn good power with it (see sig ).